Bayonet-type circuit breakers or fuses of the type contemplated herein are generally shown in U.S. Pat. No. 2,918,557 issued on Dec. 22, 1959 to E. A. Link and entitled "Circuit Breaker." In this type of a device, a bayonet assembly having a circuit bridging element is inserted into a support assembly mounted on a tank for an electrical apparatus to complete the primary circuit to a transformer immersed in insulating oil provided in the tank. Electrical communication between the circuit breaker or fuse and the circuit is provided by multiple piece contact assemblies mounted on the support assembly. Each contact assembly includes a number of contact members and a bias spring which encircles the support assembly and is threaded through the contact members. The contact members must carry current sufficient to handle transformer loading and resist the effects of arcing during switching. These functions must be maintained for the life of the device which will often exceed thirty years.